The world has experienced five pandemics in just over one hundred years, four due to influenza and one due to coronavirus (SARS‐CoV‐2). In each case of pandemic influenza, the pandemic influenza strain has replaced the previous seasonal influenza virus. Notably, throughout the SARS‐CoV‐2 pandemic, there has been a 99% reduction in influenza isolation globally. It is anticipated that influenza will re‐emerge following the SARS‐CoV‐2 pandemic and circulate again. The potential for which influenza viruses will emerge is examined.

Background During 2009‐2010, pandemic influenza A (H1N1) pdm09 virus (pH1N1) infections in England occurred in two epidemic waves. Reasons for a reported increase in case‐severity during the second wave are unclear. Methods We analysed hospital‐based surveillance for patients with pH1N1 infections in England during 2009‐2010 and linked national data sets to estimate ethnicity, socio‐economic status and death within 28 days of admission. We used multivariable logistic regression to assess whether changes in demographic, clinical and management characteristics of patients could explain an increase in ICU admission or death, and accounted for missing values using multiple imputation. Results During the first wave, 54/960 (6%) hospitalised patients required intensive care and 21/960 (2%) died; during the second wave 143/1420 (10%) required intensive care and 55/1420 (4%) died. In a multivariable model, during the second wave patients were less likely to be from an ethnic minority (OR 0.33, 95% CI 0.26‐0.42), have an elevated deprivation score (OR 0.75, 95% CI 0.68‐0.83), have known comorbidity (OR 0.78, 95% CI 0.63‐0.97) or receive antiviral therapy ≤2 days before onset (OR 0.72, 95% CI 0.56‐0.92). Increased case‐severity during the second wave was not explained by changes in demographic, clinical or management characteristics. Conclusions Monitoring changes in patient characteristics could help target interventions during multiple waves of COVID‐19 or a future influenza pandemic. To understand and respond to changes in case‐severity, surveillance is needed that includes additional factors such as admission thresholds and seasonal coinfections.

Background It is important that population cohorts at increased risk of hospitalisation and death following a COVID‐19 infection are identified and protected. Objectives We identified risk factors associated with increased risk of hospitalisation, intensive care unit (ICU) admission and mortality in inner North East London (NEL) during the first UK COVID‐19 wave. Methods Multivariate logistic regression analysis on linked primary and secondary care data from people aged 16 or older with confirmed COVID‐19 infection between 01/02/2020 and 30/06/2020 determined odds ratios (OR), 95% confidence intervals (CI) and P‐values for the association between demographic, deprivation and clinical factors with COVID‐19 hospitalisation, ICU admission and mortality. Results Over the study period, 1781 people were diagnosed with COVID‐19, of whom 1195 (67%) were hospitalised, 152 (9%) admitted to ICU and 400 (23%) died. Results confirm previously identified risk factors: being male, or of Black or Asian ethnicity, or aged over 50. Obesity, type 2 diabetes and chronic kidney disease (CKD) increased the risk of hospitalisation. Obesity increased the risk of being admitted to ICU. Underlying CKD, stroke and dementia increased the risk of death. Having learning disabilities was strongly associated with increased risk of death (OR = 4.75, 95% CI = [1.91, 11.84], P = .001). Having three or four co‐morbidities increased the risk of hospitalisation (OR = 2.34, 95% CI = [1.55, 3.54], P < .001; OR = 2.40, 95% CI = [1.55, 3.73], P < .001 respectively) and death (OR = 2.61, 95% CI = [1.59, 4.28], P < .001; OR = 4.07, 95% CI = [2.48, 6.69], P < .001 respectively). Conclusions We confirm that age, sex, ethnicity, obesity, CKD and diabetes are important determinants of risk of COVID‐19 hospitalisation or death. For the first time, we also identify people with learning disabilities and multi‐morbidity as additional patient cohorts that need to be actively protected during COVID‐19 waves.

Background Oseltamivir treatment is currently the only way of managing influenza in young infants for whom influenza vaccines are not licensed, but little data exist on the effectiveness of the treatment in this age group. Methods In a prospective study, we enrolled 431 newborn infants and followed them up for 10 months during their first respiratory season (September 2017‐June 2018). During each respiratory illness, we examined the infants and obtained nasopharyngeal specimens for determination of the viral etiology. Infants with influenza were re‐examined at short intervals, and additional nasopharyngeal specimens were obtained at each visit for measuring the viral load. All infants with symptoms <48 hours received oseltamivir treatment. The parents filled out daily symptom diaries. Results Among 23 infants with influenza A, the mean total duration of illness in oseltamivir recipients was 82.1 hours, compared with 253.5 hours in infants without treatment (P = .0003). For infants with influenza B, the corresponding durations were 110.0 and 173.9 hours, respectively (P = .03). In infants with influenza A, total symptom scores were significantly lower in oseltamivir‐treated infants at all time points between days 3 and 11 after the onset of therapy. In most children with either influenza A or B, viral antigen concentrations declined rapidly within 1‐2 days after the initiation of oseltamivir treatment. Conclusions Oseltamivir treatment of infants with influenza rapidly decreased the viral load in nasopharyngeal secretions and shortened the duration and severity of symptoms. The clinical effectiveness of oseltamivir appeared to be greater against influenza A than against influenza B infections.

Background Households represent important settings for transmission of influenza and other respiratory viruses. Current influenza diagnosis and treatment relies upon patient visits to healthcare facilities, which may lead to under‐diagnosis and treatment delays. This study aimed to assess the feasibility of an at‐home approach to influenza diagnosis and treatment via home testing, telehealth care, and rapid antiviral home delivery. Methods We conducted a pilot interventional study of remote influenza diagnosis and treatment in Seattle‐area households with children during the 2019‐2020 influenza season using pre‐positioned nasal swabs and home influenza tests. Home monitoring for respiratory symptoms occurred weekly; if symptoms were reported within 48 hours of onset, participants collected mid‐nasal swabs and used a rapid home‐based influenza immunoassay. An additional home‐collected swab was returned to a laboratory for confirmatory influenza RT‐PCR testing. Baloxavir antiviral treatment was prescribed and delivered to symptomatic and age‐eligible participants, following a telehealth encounter. Results 124 households comprising 481 individuals self‐monitored for respiratory symptoms, with 58 home tests administered. 12 home tests were positive for influenza, of which eight were true positives confirmed by RT‐PCR. The sensitivity and specificity of the home influenza test were 72.7% and 96.2%, respectively. There were eight home deliveries of baloxavir, with 7 (87.5%) occurring within 3 hours of prescription and all within 48 hours of symptom onset. Conclusions We demonstrate the feasibility of self‐testing combined with rapid home delivery of influenza antiviral treatment. This approach may be an important control strategy for influenza epidemics and pandemics.

Background Colombia's climatological variety, added to pathogen diversity, creates local niches for infectious diseases. In Bogotá, respiratory syncytial virus causes 30%‐52% of the cases of respiratory infections. In coastal or inter‐Andean cities with higher temperature and longer dry seasons, frequency of this virus is 7%‐13%. By 2017, increased hospitalizations due to airway infections occurred in regions whose weather is differently influenced by “El Niño Southern Oscillation” than in Bogotá, although microbial diversity might have also been involved. Methods For Cali, an inter‐Andean city with warm tropical weather, records of respiratory syncytial virus from 2014 to 2018, in children two years old or younger, were analyzed, and genotypes transmitted during 2016‐2017 were identified based on partial sequences of glycoprotein G. Results Most cases of respiratory syncytial virus in Cali occur in the first semesters, with peaks expressed around March‐April, without a clear association with pluviosity. Unlike the biannual rotating pattern of Bogotá, co‐circulation of types A and B was detected. As years pass, transmission seasons are becoming longer and frequencies of the virus augment. The viral genotypes identified follow international trends with dominance of Ontario and Buenos Aires clades. Similar to other isolates in these clades, viruses from Cali exhibit glycosylation variability that may account for their fitness. Conclusions The pattern of respiratory syncytial virus transmission in Cali differs from that in Bogotá. Its epidemiology is shifting and will remain so with the advent of novel respiratory diseases. This may impact the introduction of vaccination schemes for these or other respiratory viruses.

Background Physical distancing and facemask use are worldwide recognized as effective non‐pharmaceutical interventions (NPIs) against the coronavirus disease‐2019 (COVID‐19). Since January 2020, Taiwan has introduced both NPIs but their effectiveness on non‐COVID‐19 respiratory viruses (NCRVs) remain underexplored. Methods This retrospective observational study examined electronic records at a tertiary hospital in northern Taiwan from pre‐COVID (January–December 2019) to post‐COVID period (January–May 2020). Patients with respiratory syndromes were tested for both enveloped (eg, influenza virus and seasonal coronavirus) and non‐enveloped RVs (eg, enterovirus and rhinovirus) using multiplex reverse transcription polymerase chain reaction assays. Monthly positivity rates of NCRVs among adult and pediatric patients were analyzed with comparison between pre‐ and post‐COVID periods. Results A total of 9693 patients underwent 12 127 multiplex RT‐PCR tests. The average positivity rate of NCRVs reduced by 11.2% (25.6% to 14.4%) after nationwide PHIs. Despite the COVID‐19 pandemic, the most commonly identified enveloped and non‐enveloped viruses were influenza virus and enterovirus/rhinovirus, respectively. Observed reduction in NCRV incidence was predominantly contributed by enveloped NCRVs including influenza viruses. We did not observe epidemiological impacts of NPIs on non‐enveloped viruses but an increasing trend in enterovirus/rhinovirus test positivity rate among pediatric patients. Our data were validated using Taiwan's national notification database. Conclusions Our frontline investigation suggests that the current NPIs in Taiwan might not effectively control the transmission of non‐enveloped respiratory viruses, despite their protective effects against influenza and seasonal coronavirus. Health authorities may consider using hydrogen peroxide or chloride‐based disinfectants as additional preventative strategies against non‐enveloped respiratory viruses in the post‐COVID‐19 era.